SYSMEX XN-9000全自动血液分析仪有核红细胞镜检规则的建立与评价

摘要

Objective To investigate the microscopy rule for nucleated red blood cell(NRBC) by SYSMEX XN-9000 automatic hematology analyzer,and to evaluate the correction formula for white blood cell(WBC) count and NRBC.Methods Samples were determined by SYSMEX XN-9000. The results must be >0 NRBC/100 WBC. Totally,716 samples were collected. Every sample was observed by microscopy after Wright-Giemsa staining. The accuracy of SYSMEX XN-9000was evaluated,and the results were compared with those of microscopy(gold standard). The correction formula was investigated.ResultsThe correlation coefficient(r2)between SYSMEX XN-9000 and microscopy was 0.981. Bland-Altman plot showed a good consistency between the 2 methods. The 95% agreement limit of difference between the 2 methods was(-0.59±2.73) NRBC/100 WBC,and 23 samples (3.21%) was beyond the 95% agreement limit of difference. Receiver operating characteristic(ROC)curves were used to identify the optimal smear threshold value. The sensitivity was 87.3%,and the specificity was 76.5% at≥1.1 NRBC/100 WBC,while the area under ROC curve was 0.88. However,the false negative rate was 23.5%,which was against the criterion of ISO 15189(≤5%). At ≥0.3 NRBC/100 WBC,the false positive rate was 49.6%,and the false negative rate was 2.3%. If WBC count error between SYSMEX XN-9000 and microscopy was >5% [1/3 allowable total error(TEa)],the results of SYSMEX XN-9000 should be recalculated according to those of microscopy. The correction formula was WBC=(100×WBCSYSMEX XN-9000+NRBCSYSMEX XN-9000×WBCSYSMEX XN-9000)/(100+NRBCmicroscopy).Conclusions SYSMEX XN-9000 could determine NRBC in peripheral blood rapidly, accurately and effectively. WBC count should be recalculated,when there is difference between SYSMEX XN-9000 and microscopy.%目的 探讨SYSMEX XN-9000全自动血液分析仪(简称XN-9000)有核红细胞(NRBC)镜检规则以及白细胞(WBC)计数校正的方法.方法 收集716例XN-9000检出>0个NRBC/100个WBC的标本,所有标本经瑞氏染色后在显微镜下进行外周血NRBC计数.以镜检法为金标准,评估仪器法计数NRBC的准确性并制定相应的镜检规则及WBC计数的校正公式.结果 仪器法与镜检法NRBC计数结果呈明显正相关(r2=0.981).Bland-Altman分析显示仪器法与镜检法差异的95%一致性界限为(-0.59±2.73)个NRBC/100个WBC,共有23例(3.21%)标本在一致性界限范围外,二者具有良好的一致性.以人工镜检NRBC计数作为金标准绘制受试者工作特征(ROC)曲线,当设定仪器计数结果≥1.1个NRBC/100个WBC作为镜检规则时,敏感性(87.3%)和特异性(76.5%)最佳,ROC曲线下面积为0.88,但NRBC检出的假阳性率为12.7%,假阴性率为23.5%,不符合ISO 15189的要求(假阴性率≤5%);当设定仪器计数结果≥0.3个NRBC/100个WBC为镜检规则时,假阳性率为49.6%,假阴性率为2.3%,符合要求.当仪器自动校正的WBC计数结果与镜检法校正后的WBC计数结果间偏差>5%[1/3允许总误差(TEa)]时,结果应以镜检法为准,仪器计数结果需重新校正,校正公式为WBC=(100×WBC仪器+NRBC仪器×WBC仪器)/(100+NRBC镜检).结论 XN-9000能快速、准确、有效地自动计数外周血NRBC.当镜检结果与仪器检测结果差异较大时,需重新校正WBC计数.